A steam generator is described in German Pat. specification No. 1 301 821 in which fuels which cannot usually be completely condensed are burnt in a combustion chamber and the combustion gases flow through the combustion chamber to an outlet. Water is injected into the combustion gases through apertures which are disposed alongside the flow path in the side wall of the combustion chamber at the location of a duct constriction and such water evaporates owing to the elevated temperature of the combustion gases. The superheated steam generated by means of this device is used particularly for the operation of ejectors in order to operate altitude simulation systems.
Such a rocket propulsion drive combustion chamber would also be suitable for generating steam which can be used for driving a turbine. In this context, it is essential for the gas generated by the combustion chamber to be completely condensable, i.e. no combustion gas residue must remain. This requirement can be satisfied with particular advantage if hydrogen and oxygen are used as combustion gases in a stoichiometric ratio since water is produced by complete combustion. The addition of water to the hot combustion gases also reduces the temperature of the combustion gases, thus achieving a temperature of the order of 900.degree. C., which is acceptable for the operation of turbines.
The efficiency of such combustion chambers is naturally particularly high when the most uniform possible contact between the injected water and the hot combustion gases is achieved, because the evaporation rate will then be an optimum. What is desired is a steam generator which permits particularly advantageous utilisation of the thermal energy which is stored in the hot combustion gases.